Watchmaker&#39;s gage.



No. 738,723. PATBNTED SEPT. 8, 1903.

i 0. H. JENKINS.

WATCHMAKERS GAGE.

APPLICATION FILED JAN. 31, 1902.

no MODEL.

Fatented September 8, 1903 PATENT FFICE.

CHARLES HVJENKINS, OF LEBANON, NEW HAMPSHIRE, ASSIGNOR OF ONE- HALF TO FRANK B. KENDRIOK AND WILLIAM F. DAVIS, OF LEBANON,

NEW HAMPSHIRE.

'WATCHMAKERS GAGE.

' SBECIFIGATION forming part of Letters Patent No. 738,723, dated September 8, 1903.

Application filed January 31, 1902. Serial No. 91,973. (No model.)

To all whom it may concern..-

Be itknown that I, CHARLES H. JENKINS, a citizen of the United States, residing at Leb anon, in the county of Grafton and State of 5 New Hampshire, have invented certain new and useful Improvements inWatchmakers Calipers, of which the following is a specification, referencebeing had therein to the accompanying drawings.

My invention relates to improvements in calipers which are especially adapted for the use of watchmakers, and has for its object to provide a simple, efficient, and easilyadjustable mechanism notonlyfor measuring the diameter or thickness of various objects, but

also for testing the balance-wheel or other like wheel of a Watch or other similar device for truth and poise--that is to say, to provide a simple andefficient watchmakers tool that an may be readily adjusted and used not only as calipers, but also as a truing and poising tool. y

The invention consists of the novel features of construction hereinafterset forth and de-' scribed, and more particularly pointed out in the claims hereto appended.

Referring to the drawings, Figure l is a plan view of the tool. Fig. 2 is a plan view of the under side. Fig. 3 is a plan view shown 0 partly in section. Fig. 4 is an end elevation.

Fig. 5 is a detail view of the means for supporting and adjusting the caliper-points, shown partly in section, said section being takenon the line-5 5 of Fig. 3 looking in the 5 direction of the arrow. Fig. 6 is a perspecand (1*. These recessed portions extend half-' 5o way into thebar andareeach provided with a central opening 6. The said recessed por tion, the shoulders, and the central opening of one bar correspond in size and shape with the recessed portion, the shoulders, and the central opening of the other ban-that is say, the barsa and b are symmetrically and similarly formed in every respect. These bars are assembled to form a double pair of caliper-jaws m m and n n, as shown in Figs. 1

to 3, inclusive, by placing the bar a over the bar b, so that the recessed portions will dove tail or fit together and the central opening therein register, and by passing a headed bolt f through the said openings and by securing the same to a cap or plate g, through which the bolt f, likewise passes, by means of screws h h, similar to the pillarscrew of a watch, said screwsengaging with screw-threaded recesses t i in theend of said boltf. By this construction a smooth, neat, and strong pivot or joint is made and at the same time one which will permit of the cali per-arms being readily taken apart when de sired to adjust the same. The shoulders 61,

d (Z and d are so constructed and arranged that in a full-sized tool there is a space of about one-sixteenth of an inch between each pair of opposed shoulders when the arms are in the position shown in Figs. 1 and 2 of the drawings to permit the jaws to move toward and from each other.

k is a plunger actuated by the spring it, both the said plunger and spring being inserted in a hole or recess drilled in the arm 5 a, the function of this mechanism being to force the caliper-jaws toward each other, the force of the spring 75 causing the plunger 70 to press or push against the shoulder d' of the bar I), and thereby causingthe caliperjaws to move toward each other until stopped either by the shoulders d fand cF-pressing against each other or by the inner end of the adjusting stop-screw Z pressing against the shoulder d of the bar 1) whenever the inner end of said stop-screw projects beyond the .9

its function is to overcome the force of the I00 spring-plunger k and to stop the caliper-jaws from moving toward each other whenever desired. It does not prevent, however, the caliper-jaws from being moved fartherapart, a feature which is of great advantage when it is desired to remove the wheel under examination from the caliper bearings or centers with the intention of reinserting it again between the caliper-centers for reexamination and proof, as will be hereinafter more fully stated.

70 is a knurled screw passing through the arm a and adapted to bind upon the plunger 70, and its function is to hold the plunger back .whenever it is not desirable to have the arms spring-acting. If for any purpose it be desired to lock the jaws, so as to fix them in a certain adjusted relation, the set-screw 70 is bound against the plunger is and renders it inoperative and at the same time prevents the separation of said jaws. This, inconjunction with the set-screw Z or other means of'limiting the reverse movement of the jaws, will serve to effectually lock the d'evicein adj usted position.

In. the jaws m m of the arms or and b, are formed or secured suitable hearings or centers m m to receive the-shaft of the wheelfor example, thecenter-wheel of a watch-to be examined. Theseends of the calipers are especially adapted for the examination of wheels heavier and larger than the balancewheel of a watch.

0 0 denote split draw-in studs,- each provided with an opening- 19, adapted toreceive the points having recessed ends, and said studs are also provided-with a screw-threaded portion which-passes through the jaws n, n and with which screwthreaded portion the thumb-nut q is adapted to engage. Fhe jawsn 'n are especially adapted for the examinationof the more delicate wheels. ofi a watch, such as the balance-wheel and the like.

t is an indicator-bar-attaehed to and sup;- ported upon the arma bymeans ot' a taperheaded screw or stud it, carried by the arma, the said bar having one or more holes or) nearone end and the said end bein-g'separated orsplit, as at w, seem to form asp ring to bind onthe taper head ofsaid screw or stud and atthe same time permit ofi the bar beingread-ily detached from the arm. The opposite end of. said bar-t is preferably free, the said bar being maintained in thedesizred relation to-thesaid jaws by the spring connection hereto-foredescribed.

00 denotes anindicator-fingeror auxiliary indicator-bar attached to the indicator-ban t by meansof a taper-headedstudor screwy and havingoneor more holes 2 a and sepa- ,rated or split, at 2, toform a spring to bind on the taper head of said screw'on stud 1 and at the same time permit ot the fingerbar being readily detached from the indicator-bar.- i

The indicator-bar 15, carrying theindicatorfinger or auxiliary bar or, may be attached to the stud u when it is desiredto use it in conneotion with jaws m m. The indicator-bar may, however, be attached to the caliper-arm by the construction shown in Figs. 8 and 9 that is, by a split stud or screw g secured to the indicator-bar, which stud or screw is adapted to enter a hole in the caliper-arm, and thereby form a spring connect-ion between said bar and said arm and at the same time permit of-the said bar being readily detached from the said arm. The indicatorfinger may be attached to the indicator-bar ;in like mannerthat is, the split stud or .screw M, Fig. 10, is adapted to enter a hole in the indicator-bar and connected therewith in the same manner that the split stud or screw y is connected with the caliper-arm.

The mode of operation of the above-described device in so far as it has not already been disclosed is as follows: When it is desired, for example, to test the balance-wheel ofa watch, the stop-screw Z is set and adjusted so that the points or centers 1 1" will bear with suflicient force against the journals of the wheel, so as to allow the wheel to revolve freely withoutlooseness. The function of the stop-screw Z, as has been already stated, is to overcome theforce of the springplunger It, thereby relieving the journals of the wheel from too great pressure of the jaws and reducing the tendency to bend and distort the wheel to a minimum. By this con fstruction the jaws may be adjusted with 5 great convenience-and extreme delicacy so as fnot toinjure the wheel under examination. 5 The wheel havingbeen adjusted between the :lpoints, as above-stated, it becomes necessary to adjust the points so that their axes shall lie in the same. straight line. This, is-accomplish-edi by turning the points supported by the splitdraw-in stud'sby meansofi the-hand or a key-lever (not shown); until: the axes of gsaid points appear tothe eye to be in the same straight line. Thepoints are then sog curely held in: position. by the said studs by turning the-thiu mbv-n-ut g. This construction avoids the difficulty which occurs when the caliper-arms are hinged or pivoted together, g for when they are adjusted for different sizes 1 of wheelsthe points or-bearings move in arcs, and? consequently the axes of the twobearingsorceniterswill not lie in thesames-traight line, and therefore the use of the device is liimited', so faras a reliable test is concerned,

to a flew sizes 06 wheels, because the axes. of

the-bearings are at an angleto the axes. of the wheel. By the use of the adjustable lpoints above described accurate results may ibe obtained for a much greater variety of Zsizes of wheels than with instruments not lprovided with such adjustable points, and, @furthermore, a quick and ready meansis provided not only for adjusting the bearings {or points, but also for changing the same. Thewheel having been perfectly-adjusted as above stated, the indicator-finger carried by the indicator-bar is adjusted to the rim of thewheel and the wheel revolved in the ordinary way to test the wheel for truth and poise. When this hasbeen determined, the jaws are spread apart and the wheel removed and altered if found defective and replaced to verify the work. This can readily be done, because the opening and closing of the jaws does not disarrange the adjustment of any of the parts, the spring returning the bearings or centers and indicator-finger to the same positions as previously set.

What I claim, and desire to secure by Laters Patent, is-

1, In a device of theclass described, a pair I of jaws one of which is pivotally movable relative to the other, means whereby a bearing may be secured to eachjaw, adjusting mechanism, connected. with each means whereby it may be adj u'sted independently of its jawin a plane transverse to the axis of said pivotal movement and a finger-bar adapted to be supported by said jaws adjacent to said bearings. a

2. In a device of the class-described, a pair of jaws one of which is pivotally movable relative to the other, means whereby a bearing may be detachably secured to each jaw, adjusting mechanism connected with each Ma s means wherebyit may be adjusted independently of its jaw in a plane transverse to the axis of said pivotal movement and a fingerbaradapted to be supported by said jaws adjacent to said bearings. I j

3. In a device of the class described, a pair of jaws, one of which is pivotally movable relative 'to the other, means whereby a bear- 1 ing may be secured to each'jaw, adjusting mechanism connected with each means whereby it may be adjusted independently of its I jaw in a plane transverse to the axis of said I pivotalmovement and a finger-bar adapted to be supported bysaid jaws adjacent to said bearings.

i 4. In a device of the class described, a pair of jaws, one of which is pivotally movable relative to the other, a split draw-in stud car ried by each jaw whereby a bearing may be detachably secured thereto and whereby adjustment of said bearings in a plane transverse to the axis of said pivotal movement independently-of its jaw may be had, and a thumb-nut whereby said stud may be released to admit of such adjustment and reset in any desired position.

5. In a device of the class described, the

combination of a pair of jaws, a pivotal connection therefor, said jaws being provided,

adjacent to said connection with opposed shoulders, whereby the pivotal movement in,

each direction is limited,a spring-actuated plunger seated in a recess in one of said shoulders and adapted to bear against the opposing shoulder, whereby saidjaws are normally forced toward each other and means whereby said plunger may be set against movement. I a a. a

6. In a device of the class described, the combination of a pair of jaws, a pivotal connection therefor, said jaws being provided adjacent to said connection with opposed shoulders, whereby the pivotal movement in each direction is limited, a spring-actuated plunger seated in arecess in one of said shoulders and adapted to bear against the opposing shoulder, whereby said jaws are normally forced toward each other until other opposing shoulders meet, and adjustable means in connection with said last-mentioned shoulders, whereby the movement of said jaws in one direction only may beregulated,

7. In a device of the class described, the combination of a pair of jaws, a pivotal con-- nection therefor, said jaws being provided adjacent to said connection with opposed shonl-. ders, whereby the pivotal movement in each direction is limited, a spring-actuated plunger seated in a recess in one of said shoulders and adapted to bear against the opposing shoulder, whereby said-jaws are normally forced toward each other until other opposing shoulders meet, and a set-screw capable of being drawn entirely within one of said last-mentioned shoulders and adapted to bear against the opposing shoulder, whereby the movement of said jaws may be regulated.

8. In a device of the classdescribed, the

combination of two symmetrical bars provided respectively with a circularrecessintermediate their ends and diametrically opposite jaws, and a pivotal connection between said bars centrally of said recesses, comprising a cap, a headed bolt passed through said I bars and cap, and a plurality of screws adapt ed to engage respectively the shank of said bolt and said cap.

9. In a device of the class described, the

combination of a pair of jaws, a pivotal connection therefor, said jaws being provided with opposed shoulders adjacent to said conin each direction is limited, a spring-actuated IIO I nection, whereby the movement of said jaws plunger seated in'a recess in one of said shoulders and adapted to bear against the opposing shoulder, whereby said jaws are forced toward each other until other opposed shoulders meet, adjustable means in conjunction with said last-mentioned shoulders I whereby themovement of said jaws under the and means whereby said plunger may be set influence of said plunger may be regulated,

in any desired position to lock the device.

1 10. In a device of the class described, a

jaws and an indicator-bar having a plurality of openings therein, said stud being adapted .pair of jaws, a stud carried by one of said to pass through said openings respectively and; be frictionally engaged by said bar.

11. In a device of the class described, a;

pair of jaws, an indicator-barprovided with;

a bifurcated spring portion, and means in I conjunction with said spring portion wherel l by said bar may be secured to one of said" jaws. I I I 12. In a device of the class described, a pair of jaws, an indicator-bar; a stud on said bar, means whereby said bar may be secured relative to said jaws, a finger-bar having a plurality of openings therein adapted to engage said stud, whereby it may be frictionally and detachably secured to said indicatorbar by means of said stud.

13. Ina device of the class described, a

pair of jaws, an indicator-bar, means where said pivotal movement, means for imparting pivotal movement to said jaw and a fingerbar adapted to be supported by said jaws alijacent to said bearings.

15. In adevice of the class described, a-

pair of jaws one of which is pivotally movable relative to the other, means whereby a hearing may be detachably secured to each jaw, adjusting mechanism connected with each means whereby it may be adjusted independently of its jaw in a plane transverse to the axis of said pivotal movement, means for imparting pivotal movement to said jaw and a finger-bar adapted to be supported by said jaws adjacent to said bearings.

16. .In a device of the class described, a pair of jaws one of which is pivotally movable relative to the other, means whereby a bearing may be secured to each jaw, adjusting mechanism connected with each means whereby it may be adjusted independently of its jaw in-a plane transverse to the axis of said pivotal movement, and set in a desired position, means for imparting pivotal move- "ment to said jaw and a finger-bar adapted to be supported by said jaws adjacent to said bearings.

In witness whereof I have hereunto set my signature, this 16th day of January, 1902, in the presence of two witnesses.

CHARLES H. JENKINS.

Witnesses:

N. O. BRIDYMAN, M". D. COBLEIGH. 

